284 
PRINCIPLES OP GUNNERY. 
In the descending branchy compute from 0 to 34*2°; then 
/3 = 34*2°, D = 34*2°, 
tan 34° 12' 
tan <jb 1 = 
•3398; 
or ^ = 18° 46', 
$ = 577*8, andy? sec ^ = 610*3, 
d 2 
/ loop y_ ^ 
\<Z sec yj “ “ 
X 34-2 X sec 18° 46' 
9*5466 
= 1*319 + 4*400 = 5*719, 
or q sec t/h = 559*2 f.s., and q = 529*5 ; 
+ 
( 
1000 
\610 
10 V 
•y 
then q> = 18° 46' — 
578 — 530 34° 12' 
578 + 530 3 
— 18° 46' — 30' = 18° 16', 
/72 
|r = cosl8°16' 
or r = 6334 ft., 
Y' = X' tan 18° 16'= 2091 ft., 
J(^.-W= 8-984 x| 
= 11*43 secs., 
range = X + X' = 6726 + 6334 
tf 559 . 3 = 16316 
^610*3 = 43991 
2325 
= 30-281 
y 61 „. 3 = 16-297 
8-984 
time of flight 
o 
= 13060 ft. 
= 4353 yds., 
T + T' = 11*06 + 11*43 = 22*49 secs., 
and Y— Y' = 2086 — 2091 = — 5 ft. 
or the projectile strikes 5 ft. below the horizontal line. 
From above, 
% 
so that 
q = 529*5, 
striking velocity = 529*5 sec 34° 12' = 640*3 f.s. 
The same example worked out more carefully by Bashfortlfis method 
of solution gives 
range = 13197 ft. = 4399 yds. 
time of flight = 22*87 secs, 
and striking velocity = 635 f.s. 
When the experiments for determining the coefficients for velocities 
below 900 f.s. are completed, and Tables I., II., and III. extended in 
accordance with the results observed, the solution of high-angle tra¬ 
jectories will be approached with greater confidence. 
{To be continued.) 
